Diabetes, primarily type 2 diabetes (T2DM), has reached epidemic proportions among Mexican Americans in the US-Mexico border region, making this unique geopolitical region one that should be targeted for eliminating T2DM health disparities among a highly vulnerable population. Multiple and diverse characteristics of the border region such as poverty, language and health literacy barriers propagate T2DM health disparities. In addition, diabetes self-management education programs that target individuals and have very limited consideration of the family context have contributed to limited health care access. The family is a critical social context in which disease management occurs for Mexican American adults with T2DM. Yet few studies have capitalized on the strong cultural value of family (familismo) for T2DM management among adults in this region. We propose a unique approach for reducing T2DM health inequities and building family social capital - the application of community based participatory research (CBPR) principles with Mexican American adults with T2DM and their family partners to design and test a culturally tailored diabetes self-management education, social support intervention. A mixed method approach will be implemented in two phases to address 3 aims. In Phase 1 (Aim 1) using the principles of CBPR we will engage Mexican Americans adults with T2DM and a family partner (n=20) to refine a diabetes education and social support intervention within a family context. In Phase 2 (Aims 2, 3) using a randomized experimental design, we will implement the 6-month intervention and test its immediate and sustained effects. A total of 168 Mexican American adults with T2DM, ages 35-74, and their family partner, age 18 and older, will be randomly assigned to either intervention or wait list control groups. Data will be collected at baseline, immediately post intervention, and 6 months post intervention to measure behavioral outcomes (diabetes self management, diabetes self efficacy, diabetes distress, nutrition and physical activity behaviors), biologic outcomes (glycemic control) and family social capital outcomes (social integration, family efficacy, family social support, health literacy, health care access) Findings are expected to reduce T2DM health disparities by expanding the approach underpinning T2DM self management education programs, and improve and sustain glycemic control, with potential positive downstream effects for the individual's family and community as well.